The hypothesis that the specific decreases in collagen synthesis in bone of scorbutic guinea pigs is due mainly to the decreased food intake and weight loss of scurvy was further substantiated. There was a linear relationship between the percentage of collagen synthesis and the extent of weight change in scorbutic and food-restricted controls receiving vitamin C, compared to ad libitum fed controls. The fact that this decrease occurs independently of the effects of scurvy on hydroxylation of proline in collagen, represents a new concept for the mechanism of action of ascorbate on connective tissue. Four days of acutely fasting guinea pigs receiving ascorbate specifically decreased collagen production in guinea pig calvaria and other connective tissues by 70-80%. Collagen synthesis in other connective tissues was equally susceptible to the effect of fasting. The mechanism of this effect is being investigated. It also has been found that the intracellular levels of cAMP in a series of normal and Ki-MSV transformed BALB 3T3 cells are similar, although the rates of collagen production are decreased in the transformed cells. Those studies suggest that cAMP is not involved in maintaining the transformed phenotype in BALB 3T3 denved cells.